1215451165 has 8 divisors (see below), whose sum is σ = 1471449528. Its totient is φ = 963755520.

The previous prime is 1215451157. The next prime is 1215451183. The reversal of 1215451165 is 5611545121.

It can be written as a sum of positive squares in 4 ways, for example, as 90117049 + 1125334116 = 9493^2 + 33546^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1215451165 - 2³ = 1215451157 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1075056 + ... + 1076185.

It is an arithmetic number, because the mean of its divisors is an integer number (183931191).

Almost surely, 2^1215451165 is an apocalyptic number.

It is an amenable number.

1215451165 is a deficient number, since it is larger than the sum of its proper divisors (255998363).

1215451165 is a wasteful number, since it uses less digits than its factorization.

1215451165 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2151359.

The product of its digits is 6000, while the sum is 31.

The square root of 1215451165 is about 34863.3211986466. The cubic root of 1215451165 is about 1067.2000528432.

Adding to 1215451165 its reverse (5611545121), we get a palindrome (6826996286).

It can be divided in two parts, 121545116 and 5, that added together give a palindrome (121545121).

The spelling of 1215451165 in words is "one billion, two hundred fifteen million, four hundred fifty-one thousand, one hundred sixty-five".